<template>
  <div class="cmt-container">
    <h3>发表评论</h3>
    <hr />
    <textarea placeholder="最多评论120字" maxlength="120" v-model="msg"></textarea>
    <mt-button type="primary" size="large" @click="postComment">发表评论</mt-button>
    <div class="cmt-list">
      <div class="cmt-item" v-for="(item,i) in comments" :key="item.add_time">
        <div class="cmt-title">
          第{{i+1}}楼 &nbsp;&nbsp;用户：{{item.user_name}}&nbsp;&nbsp;发表时间：{{item.add_time | dataFormat}}
        </div>
        <div class="cmt-body">{{item.content==='undefined'?'此用户很懒，什么都没说':item.content}}</div>
      </div>
    </div>
    <mt-button type="primary" size="large" plain @click="getMore">加载更多</mt-button>
  </div>
</template>

<script>
import{Toast} from "mint-ui";
export default {
  data() {
    return {
      pageindex: 1,
      comments: [],
      msg:''
    };
  },
  methods: {
    getComments() {
      this.$http
        .get("api/getcomments/" + this.id + "?pageindex=" + this.pageindex)
        .then((result) => {
          if (result.body.status === 0) {
            // this.comments = result.body.message;
            // 每当获取新评论数据时，不清空数据，实现数据拼接
            this.comments =this.comments.concat(result.body.message)
          } else {
            Toast("获取评论失败！");
          }
        });
    },
    getMore(){
      this.pageindex++,
      this.getComments()
    },
    postComment(){
      if(this.msg.trim().length===0){
        return Toast("评论内容不能为空");
      }
      // 发表评论
      // 参数1：请求的url地址
      // 参数2：提交给服务器的数据对象{conten：this.msg}
      // 参数3： 定义提交时候，表单中数据的格式{emulateJSON：true}
      this.$http.post('api/postcomment/'+this.$route.params.id,{
        content:this.msg.trim()
      })
      .then(function(result){
        if(result.body.status===0){
          var cmt ={
            user_name:'匿名用户',
            add_time:Date.now(),
            content:this.msg.trim()  //去除字符串的头尾空格
          };
          this.comments.unshift(cmt);
          this.msg=""
        }
      })
    }
  },
  props: ["id"],
};
</script>

<style lang="scss" scoped>
.cmt-container {
  h3 {
    font-size: 18px;
  }
  textarea {
    font-size: 14px;
    height: 85px;
    margin: 0;
  }
  .cmt-list {
    margin: 5px 0;
    .cmt-item {
      font-size: 13px;
      .cmt-title {
        line-height: 30px;
        background-color: #ccc;
      }
      .cmt-body {
        line-height: 35px;
        text-indent: 2em;
      }
    }
  }
}
</style>